library of chromatic induction & contrast

 

This is the index page to 114 image files that demonstrate chromatic induction (assimilation), color contrast, and the effects of color combinations in large area patterns, small area textile patterns, and subtractive mixtures. Each file is in GIF format to eliminate compression artifacts.

Hues are presented in four different gamuts: (1) high luminance, or hues displayed near the peak chroma allowed in the Photoshop RGB (computer monitor) gamut; (2) nuance, or hues displayed at the same lightness and approximately the same chroma; and in CYMK gamut versions of the (3) high luminance and (4) nuance versions. The CYMK simulates printed colors, and further curbs the computer monitor gamut, especially in greens, blues and violets.

Display of spatial frequency or the visual width of color areas can be varied by loading the image into image processing software on your computer, and using the zoom function to expand or reduce the image scale on your computer monitor. (Limited zoom capability is also available in both the Safari and Firefox web browsers in the Apple OS.)

Many of the image files are large — 3 megabytes or more. The file size is noted in the image link, to help you manage your download choices.

 
high luminance color combinations

Location of high luminance colors on the CIELAB a*b* plane showing the 12 target hues (assimilation background or contrast central square) as larger dotted circles, and the 12 contrast hues (assimilation overlay or contrast background squares) as smaller circles. The diagram illustrates the hue circle distance between overlay/contrast hues in the analogous (1), near analogous (2), quadratic (3), triadic (4), near complementary (5) and complementary (6) displays. Note the strong curbing of blue green and violet colors by the computer monitor gamut limits.

In each image file, 12 chromatic and 1 middle gray target hues are presented with all 12 possible combinations of overlay/contrast hues, to create 156 chromatic induction examples. An additional 24 examples present the target hues with black/white or with two gray overlay/contrast colors. In all files, the minimum contrast displays are marked with white dot; complementary contrast displays by a black dot.

Assimilation files are dimensions of about 2800 x 3100 pixels. Contrast files are dimensions of about 3500 x 2500 pixels.

chromatic assimilation

• 1 analogous (assimilation overlays separated by 1 hue category)
   computer gamut version (244Kb) - CYMK gamut version (3273Kb)

• 2 near analogous (assimilation overlays separated by 2 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3045Kb)

• 3 quadratic (assimilation overlays separated by 3 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3070Kb)

• 4 triadic (assimilation overlays separated by 4 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3041Kb)

• 5 near complementary (assimilation overlays separated by 5 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3057Kb)

• 6 complementary (assimilation overlays separated by 6 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3029Kb)

chromatic contrast

• 1 analogous (contrast backgrounds separated by 1 hue category)
    computer gamut version (150Kb) - CYMK gamut version (3050Kb)

• 2 near analogous (contrast backgrounds separated by 2 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (3047Kb)

• 3 quadratic (contrast backgrounds separated by 3 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (3049Kb)

• 4 triadic (contrast backgrounds separated by 4 hue categories)
    computer gamut version (150Kb) - CYMK gamut version (3045Kb)

• 5 near complementary (contrast backgrounds separated by 5 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (3051Kb)

• 6 complementary (contrast backgrounds separated by 6 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (3051Kb)

 
nuance color combinations (L = 65, C = ~55)

Location of nuance colors on the CIELAB a*b* plane showing the 12 target hues (assimilation background or contrast central square) as dotted larger circles, and the 12 contrast hues (assimilation overlay or contrast background squares) as smaller circles. The diagram illustrates the hue circle distance between overlay/contrast hues in the analogous (1), near analogous (2), quadratic (3), triadic (4), near complementary (5) and complementary (6) displays. Note the slight curbing of blue green and violet colors by the computer monitor gamut: chroma was chosen to maximize color saturation while minimizing the effect of the gamut limits.

In each image file, 12 chromatic and 1 middle gray target hues are presented with all 12 possible combinations of overlay/contrast hues, to create 156 chromatic induction examples. An additional 24 examples present the target hues with black/white or with two gray overlay/contrast colors. In all files, the minimum contrast displays are marked with white dot; complementary contrast displays by a black dot.

Assimilation files are dimensions of about 2800 x 3100 pixels. Contrast files are dimensions of about 3500 x 2500 pixels.

chromatic assimilation

• 1 analogous (assimilation overlays separated by 1 hue category)
   computer gamut version (244Kb) - CYMK gamut version (3008Kb)

• 2 near analogous (assimilation overlays separated by 2 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3168Kb)

• 3 quadratic (assimilation overlays separated by 3 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3167Kb)

• 4 triadic (assimilation overlays separated by 4 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3166Kb)

• 5 near complementary (assimilation overlays separated by 5 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3166Kb)

• 6 complementary (assimilation overlays separated by 6 hue categories)
   computer gamut version (244Kb) - CYMK gamut version (3132Kb)

chromatic contrast

• 1 analogous (contrast backgrounds separated by 1 hue category)
    computer gamut version (150Kb) - CYMK gamut version (2807Kb)

• 2 near analogous (contrast backgrounds separated by 2 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (2808Kb)

• 3 quadratic (contrast backgrounds separated by 3 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (2804Kb)

• 4 triadic (contrast backgrounds separated by 4 hue categories)
    computer gamut version (150Kb) - CYMK gamut version (2807Kb)

• 5 near complementary (contrast backgrounds separated by 5 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (2807Kb)

• 6 complementary (contrast backgrounds separated by 6 hue categories)
   computer gamut version (150Kb) - CYMK gamut version (2805Kb)

 
textile patterns

Twelve target hues (diagram, above left) in both high luminance (outer circle) and nuance (inner circle) versions are used to generate textile patterns.

Three colors appear in each textile pattern, either as diagonal rows or the background, in the visual area proportions 10:11:30 (right diagonal:left diagonal:background). Each assortment of 3 colors is presented three times, side by side, with each color as the background; each set of three is presented twice, in high luminance (upper textile row) and nuance (lower textile row) versions (images, below).


standard version


CYMK version

example textile patterns in red orange, blue and green

There are 14 image files, with 330 unique textile patterns in each file. In 12 files, a single base hue, present in every pattern, is combined with the 55 possible pairwise selections of the remaining 11 hues. Two files present the combinations of all 12 hues with black or white as the background color.

At the top of each file is a numerical key to the 11 hues other than the base hue. Key numbers are placed at the top left of each textile combination, and patterns are ordered in increasing numerical order. To find a specific color assortment, first choose the base file for one color, then use the numerical key to identify the number combination for the remaining two colors.

Every color combination appears in three image files, with each color as the base hue: choose the base hue wanted to compare patterns that contain the same color.

Base hue files are dimensions of 2035 x 3120 pixels. Achromatic (black or white) files are dimensions of 2035 x 3960 pixels.

• yellow base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• yellow orange base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• red orange base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• red base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• red violet base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• violet base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• blue violet base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• blue base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• green blue base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• blue green base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• green base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• yellow green base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• white base hue:
   standard version (684Kb) - CYMK version (2939Kb)

• black base hue:
   standard version (684Kb) - CYMK version (2939Kb)

 
lightness contrasted textile patterns

These textile patterns select three hues from the hue circle shown above, and vary each of the three hues in lightness from L* = 90 to L* = 30 in increments of 10, a total of 7 displays of 3 different colors, plus the combination of all three hues at matching lightness, for a total of 28 patterns per image file.

Pattern are organized around a quadratic selection of hues, for example (in the file 1 - 4 - 7 - 10) 1 - 4 - 7, 1 - 4 - 10, 1 - 7 - 10 and 4 - 7 - 10, the remaining hues in each textile pattern are in either a quadratic, near analogous or analogous relationship with each base hue.

• analogous contrast 1 - 4 - 7 - 10:
   standard version (844Kb) - nuance version (3750Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3590Kb)

• analogous contrast 2 - 5 - 8 - 11:
   standard version (844Kb) - nuance version (3660Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3590Kb)

• analogous contrast 3 - 6 - 8 - 12:
   standard version (844Kb) - nuance version (3500Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3640Kb)

 
• near analogous contrast 1 - 4 - 7 - 10:
   standard version (844Kb) - nuance version (3750Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3590Kb)

• near analogous contrast 2 - 5 - 8 - 11:
   standard version (844Kb) - nuance version (3660Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3590Kb)

• near analogous contrast 3 - 6 - 8 - 12:
   standard version (844Kb) - nuance version (3500Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3640Kb)

 
• quadratic contrast 1 - 4 - 7 - 10:
   standard version (844Kb) - nuance version (3750Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3590Kb)

• quadratic contrast 2 - 5 - 8 - 11:
   standard version (844Kb) - nuance version (3660Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3590Kb)

• quadratic contrast 3 - 6 - 8 - 12:
   standard version (844Kb) - nuance version (3500Kb)
   CYMK standard version (844Kb) - CYMK nuance version (3640Kb)

 
three color harmonies

  

Tile figures showing 64 mixtures among three colors: two "primary" colors (show as pure colors along the side of the tile pattern) and one "illuminant" color at lower tinting strength (shown as a pure color along the bottom).

The graph above shows the chromaticity boundary of the gamut of the RYG and MRC mixtures on the CIELAB a*b* plane.

Files are presented on a single page, with a key to the color combinations shown at the top.

• three color harmonies:
   standard version - CYMK version

 
© 2010 Bruce MacEvoy